January 16, 2013

Your brain on Big Bird

Using brain scans of children and adults watching Sesame Street, cognitive scientists are learning how children’s brains change as they develop intellectual abilities like reading and math.

The novel use of brain imaging during everyday activities like watching TV, the scientists say, opens the door to studying other thought processes in naturalistic settings and may one day help to diagnose and treat learning disabilities.

Scientists are just beginning to use brain imaging to understand how humans process thought during real-life experiences. For example, researchers have compared scans of adults watching an entertaining movie to see if neural responses are similar across different individuals. “But this is the first study to use the method as a tool for understanding development,” says lead author Jessica Cantlon, assistant professor of brain and cognitive sciences.

Eventually, that understanding may help pinpoint the cause when a child experiences difficulties mastering schoolwork.

“Psychologists have behavioral tests for trying to get to the bottom of learning impairments, but these new imaging studies provide a totally independent source of information about children’s learning based on what’s happening in the brain,” says Cantlon.

The neuroimaging findings are detailed in a new study published this month by PLoS Biology by Cantlon and her former research assistant Rosa Li, now a graduate student at Duke University.

For the investigation, 27 children between the ages of 4 and 11 and 20 adults watched the same 20-minute Sesame Street video. Like the regular program, the recording featured a variety of short clips focused on numbers, words, shapes, and other subjects. The children then took standardized IQ tests for math and verbal ability.

To capture the neural response to the show, the researchers turned to functional magnetic resonance imaging (fMRI) scans. The study produced 609 scans of each participant, one every two seconds, as they watched the program. Using statistical algorithms, the researchers then created “neural maps” of the thought processes for the children and the adults and compared the groups.

The result? Children whose neural maps more closely resembled the neural maps of adults scored higher on standardized math and verbal tests. In other words, the brain’s neural structure, like other parts of the body, develops along predictable pathways as we mature.

Using normal activities, like TV watching, may provide a more accurate indicator of children’s learning and brain development in the real world than the short and simple tasks typical of fMRI studies, the authors say.

Although the study does not advocate TV watching, it does show that “neural patterns during an everyday activity like watching television are related to a person’s intellectual maturity,” says Cantlon. “It’s not the case that if you put a child in front of an educational TV program that nothing is happening—that the brain just sort of zones out. Instead, what we see is that the patterns of neural activity that children are showing are meaningful and related to their intellectual abilities.”